Extension-ladder.



No. 873,110. v PATENTED DEC. 10, 1907.

W. WILLIAMSON.

EXTENSION LADDER. APPLICATION FILED APR. 28,1906.

WITNESSES:

\NVENTOR 5 cm, WAsHlNcnrN. a. c

WILLIAM WILLIAMSON, OF SAGINAW, MICHIGAN.

EXTENSION-LADDER.

Specification of Letters Patent.

Patented Dec. 10, 1907.

Application filed April 26. 1906. Serial No. 813.813.

T 0 all whom it may concern:

Be it known that 1, WILLIAM WILLIAMSON, a citizen of the United States,residing at Saginaw, in the county of Saginaw and State of Michigan,have invented certain new and useful Improvements in Extension-Ladders;and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as 'wdll enable others skilled in theart to which it appertains to make and use the same.

My invention relates to an extension ladder and I have hereinillustrated one embodiment of which my invention is susceptible.

One object of my invention is to provide a novel form of ladder overthose heretofore noted, capable of extension and contraction, one of thenovel features residing in the fact that the ladder sections areseparable from each other by moving the extension section downwardly.

Another important object of my invention is the provision of meansadapted to operate as a reinforcing guide strip for the base sec tion ofthe ladder, such strip performing many important functions such aspreventing side sway of the ladder when in use, strengthening the ladderconsiderably and preventing the splitting of any cross grain timber inthe base section.

Still another object of my invention is the provision of an improvedmeans for effecting the raising and lowering of the extension section,such means comprising a peculiar fastening means to which a flexibleconnection is removably secured.

Another object of my invention is the provision of means carried by theextension section and actuated by a rolling round, on the extensionsection, said means adapted to take over the rounds of the stationary orbase section to adjustably support the extension section at any desiredheight.

To these and other ends, my invention consists in certain novel featuresand combinations of parts, together with their equivalents, such as willbe more fully disclosed hereinafter and particularly pointed out in theclaims.

In the accompanying drawings illustrating one embodiment of myinvention, Figure 1 is a front view of one form of my invention whenused as an extension ladder, Fig. 2 is a detail perspective view of thelower end of the extension section, Fig. 3 is a vertical sectional viewon line .rm of Fig. 1, Fig. 4 is a detail view of the fingers engaged bythe flexible connection, and Fig. 5 is a detail side view of one of thelatches and its cooperating parts.

Referring to the drawings, A indicates the base section and B theextension section of a ladder constructed in accordance with myinvention. The foot of the base section may be spread as-shown, althoughthis is not a necessary incident of my device.-

1 preferably secure reinforcing guide strips 1, 1, to the rails of thebase section, as shown, which strips not only operate to prevent sidesway of the ladder and greatly strengthen the same, but also prevent thebreaking of the rails in case of cross grain timber or knots as well aspreventing the splitting of the rails. Furthermore, the strips whoseimportance cannot be exaggerated, are arranged to lap over or overhangthe inner faces of the rails for a purpose hereinafter set forth.

Brackets 3, 3, are securedto the inner faces of the rails of the. basesection, such brackets being each provided with an extension 4, fromwhich projects a pin 5, the pins projecting toward each other from theopposite rails. The pins 5, 5, maybe headed or not, as convenient.

The extension section is preferably narrower than the base section andoverlies the face thereof.

The pins 5, 5, project over the rails of the extension section wherebythe latter is securely held against lateral movement away from the basesection.

As one means for supporting the extension section at varying elevations1 preferably provide the following mechanism. The lower round 13 of theextension section is rotatably journaled in the side rails as by meansof the pintles 14, 14, received in bearings 15, in the side rails, thepintles being of less diameter than the round whereby to prevent alongitudinal movement thereof. At opposite ends of the round 13, Isecure the sleeves 16, 16, from which project the arms 17, 17, havingthe studs 18, 18, located at the upper free ends, the studs extending inopposite directions. A double latch 19, of A shape in general formationis pivotally secured at its apex to the inner face of each rail of theextension section, at a point between the round 13 and the round nextabove, the latches each being suitably braced as at 20, 20, the braceshaving slots 21, 21, formed therein in which are loosely received the tosecure sockets 30, 30, to the inner faces of the rails of the adjustablesection, the sockets adapted to receive the apices of the latches andassisting in the support of the weight of the adjustable section and theoperator thereon, the pivot pin passing through the socket and latch.Ordinarily this means of adjusting the extensible section is sufficientsince an operator accustomed to such structures can mount the basesection pushing the extensible section before him from time to time, thebosses or rolls 11 or 12 engaging the wall and. reducing the frictionwithout marring the surface, but for convenience of others and tofacilitate the use of the device, Iprefer to equip the rotatable round13 with a pair of suitably curvedfingers 22, 22, the fingers beingcurved in opposite directions as shown and adapted-to engage and hold aflexible connection 23, which connection may have a knot or otherenlargement 24 formed intermediate its ends and caught in the fingers.The plies of the connection ass upward on opposite sides of therotatable round and thence between the rounds ofthe extension and basesections respectively thence over a double block or pulley 25 secured tothe upper round of the base section from whence the ends depend inposition to be grasped by the operator. A pull on either end of theconnection will operate to raise the extensible section, strain on oneply being adapted to rock the rotatable round in one direction to movethe inner lip of the latch away from the rounds of the base section, andpull on the remaining ply operating to rock the round in the oppositedirection and cause the inner lip of the latch to overhang the rounds ofthe base section. Thus it will be seen that in operating the ladder adownward pull can be given both plies of cord until the latches havecleared the round on the base section over which their inner lips havecaught, whereupon the weight of the extension section may be supportedfor an instant on one of the plies alone thereby rocking the round andcatches as set forth to prevent the inner lips from engaging the roundsof the base section after which the extensible section may be raised orlowered and when in its adjusted position, a preponderance of strain isapplied to the other ply whereby to rock the latch in the oppositedirection and cause its lip to engage the adjacent round of the basesection. In this manner, the extensible section need not be loweredbelow the point at which it is to be adjusted nor need itbe raised abovethe base round on which it is to be supported only that the rounds ofthe base and extensible sections are so arranged that they lie oppositeeach other to afford a broadsupport for the feet, rather thanalternating with each other. Furthermore, the flexible connection can beinstantaneously removed from the ladder and need not be used.

The extensible section is removable from either end of the base section,that is to say, it can be run up so that the foot of the extensiblesection leaves the head of the base section or the extensible sectioncan be drawn downwardly until its head clears the inwardly projectingpins 5, 5 which latter mode is much easier to accomplish. It will alsobe observed that the latches are double, that is to say, each latch hastwo depending lips, one object of which is to provide a stopfor thelatch when its inner lip is caught over around on the base section, theouter lip taking against the sleeve 16, to limit the inward movement ofthe latch and also when the latch is removed from its engagement with around on the base section, the inner lip engages the sleeve 16 to limitthe outward movement of the latch. Another result attained by this construction is to permit the extensible section to be reversed in case itbecomes warped or sprung, or for any other reason. The reinforcingstrips 1, 1, operate to prevent the springing or warping of the basesection.

. While I have shown but two sections of an extension ladder, it isplain that more might be used, a plurality of adjustable sections beingsuccessively arranged relative to each other.

From the foregoing, it is obvious that I have devised a novelconstruction which is both simple and efiicient and one which can beplaced on the market at a comparatively slight cost.

It is also evident that many changes might be made in the form andarrangement of the several parts described without departing from thespirit and scope of my invention, hence I do not wish to limit myself tothe exact construction herein. set forth.

Having thus fully disclosed my invention, what I claim as new, is

1. The combination with a base section and an extensible section, of arocking round on the extensible section, double latches pivotallysecured to the extensible section, and arms projecting from the roundand positively engaging the respective latches to swing the lattertoward and from the rounds of the base section, the latches adapted totake over the rounds of the base section to sustain the extensiblesection in adjusted position. i

2. The combination with a base section and an extensible section, of arocking round on the extensible section, double latches pivotallysecured to the extensible section, the latches being apertured, armsprojecting from the round, studs carried by the arms and receivable inthe apertures in the latches to'positively swing the latches toward andfrom the rounds of the base section.

3. The combination with a base section and an extensible sectionslidable relative to the base section, of a rocking round on theextensible section, double latches pivotally secured to the extensiblesection, arms proj ecting from the round and positively engaging therespective latches to swing the latter toward or from the rounds of thebase section, the latches adapted to take over the rounds of the basesection to sustain the extensible section in adjusted position,oppositely extending curved fingers on the rocking round and a flexibleconnection having an enlargement in the bight thereof, for engaging thefingers.

4. An extension ladder comprising base and adjustable sections, latchespivotally supported by the adjustable section for supporting the latterat various points relative to the base section, a rocking rung,meansconnecting the rung and latches, oppositely curved fingers mountedon the rocking rung and a knotted flexible connection independent of themeans, connecting the rung and latches for actuating the rung in oposite directions, the knot being releasably eld by i I the curvedfingers.

5. An extension and extensible sections, a latch on the extensiblesection for supporting the same at various heights relative to the basesection, a rocking rung, means connecting the rung and latch, curvedfingers mounted on the rung and a flexible connection independent of themeans connecting the rung and latch, and an enlargement locatedintermediate the ends of the connection, the enlargement beingreleasably caught in the curved fingers to rock the rung in oppositedirections.

"In testimony whereof, I afiix my signature I in presence of twoWitnesses.

WILLIAM WILLIAMSON.

Witnesses:

A. A. EAsTERLY, RALPH S. WARFIELD.

ladder comprising base

